Biological Sciences and Water Resources Review

Assessment Structure and Fundamental Concepts

The academic evaluation for this course includes a variety of formats designed to test comprehensive understanding. Students will be required to complete multiple-choice questions, provide short-answer responses, and create/label detailed biological diagrams. Furthermore, essay questions will be utilized to assess the ability to synthesize complex topics. Key foundational areas of study include the classification of atoms and molecules and the classification of cells. Additionally, the curriculum covers the specific types of molecular bonding that form the basis of biological structures.

Water Resources: Rights, Distribution, and Global Use

A significant portion of the course focuses on water and the environment, specifically the rights and distribution of water resources. Water use is categorized into four primary segments. The transcript explicitly identifies domestic, recreational, and hydroelectric power generation as core components. This distribution is governed by specific legislation that regulates how water is utilized within a territory. Water policy is a framework established by governments to guide water use and allocation across different sectors and neighboring countries.

Policies are often dictated by the state of the country and its population density. However, a notable ethical and practical concern discussed is that governments often prioritize industrial water needs over domestic requirements. In many instances, the state allocates more water to agricultural plants and industrial processes than to the needs of individual citizens.

Geopolitical Water Conflicts

The scarcity of water has led to the prediction that future wars will be fought over water rights rather than land or other resources. Two primary case studies illustrate this tension:

1. The River Nile: A major conflict exists between Ethiopia and Egypt concerning the Grand Ethiopian Renaissance Dam (GERD). Egypt, located downstream, faces significant risks because the dam is built upstream in Ethiopia, potentially affecting Egypt's primary water source.

2. The Euphrates River: This conflict involves Turkey, Syria, and Iraq. Turkey is currently utilizing the majority of the water from the Euphrates, leading to a significant drop in water levels for the downstream nations of Syria and Iraq.

Water Pollution, Superbugs, and Antibiotic Resistance

Water pollution presents severe health risks, particularly the emergence of superbugs. This issue arises when members of the population become infected with bacterial pathogens, such as $Streptococcus$ or certain strains of flesh-eating bacteria. Typically, a medical consultation results in a prescribed antibiotic regime lasting $5$ to $6$ days. However, when these antibiotics are consumed, humans excrete residual amounts through urine into the wastewater system.

Once introduced into the water system, these antibiotic residues interact with the environment, causing local plants and bacteria to develop antibiotic resistance. It is estimated that by the years $2028 \times 2030$, most current antibiotics will no longer be effective. Consequently, individuals exposed to common infections will suffer severe consequences, including death, due to this lack of effective treatment.

Microbiological Hazards in Water Systems

Certain microbes pose persistent threats to water safety due to their evolutionary adaptations. Thermophiles have adapted to high temperatures, meaning some microbes can survive even if the water is boiled to kill them. Microbes are also capable of rapid growth on organic matter, such as fish.

In the human body, the large intestine contains various bacteria, including $E. coli$ ($Escherichia\,coli$). These are generally considered negative bacteria when they leave their natural environment in the gut and are exposed to other parts of the body or external systems, causing severe infections. Such bacteria are classified as coliforms. Another significant pathogen is $Giardia$, which is contracted by swallowing untreated water from contaminated sources such as lakes and streams. A local example of a significant water source is the Wag Water River, which flows from St. Andrew into St. Mary.

Macromolecules and the Cellular Membrane

Biological systems are built from four classes of macromolecules: proteins, carbohydrates, fats and oils (lipids), and nucleic acids. The structure and function of the cell membrane are central to cellular health. The membrane is defined as a phospholipid bilayer described by the fluid mosaic model.

Temperature significantly affects the structure of cell membranes. To maintain functionality, cells undergo a continuous change in the amount of cholesterol within the membrane to ensure it remains fluid. Cholesterol acts as a critical temperature buffer; it prevents the membrane from becoming too rigid in cold temperatures or too fluid in high temperatures, thereby protecting the cell's integrity.

Cellular Respiration and Glycolysis

The study of metabolism includes a rigorous review of respiration, specifically the electron transport chain and the $10$ steps of glycolysis. Students must master all substrates, enzymes, and the input/output of energy for each phase. This includes identifying the specific enzymes that activate each of the $10$ stages of the glycolytic pathway.

Photosynthesis: Light and Dark Reactions

Chapter $10$ details the process of photosynthesis, encompassing both light-dependent and light-independent (dark) reactions. Key concepts include:

1. Photosystems: The transition and movement from Photosystem II ($PSII$) to Photosystem I ($PSI$), involving the reaction centers $P680$ and $P700$.

2. Carbon Fixation Pathways: The differences and mechanisms of $C_3$, $C_4$, and $CAM$ ($Crassulacean\,Acid\,Metabolism$) plants, as well as the details of the Calvin Cycle.

Genetics, Heredity, and Molecular Biology

Genetics topics cover meiosis, specifically comparing the stages in Meiosis I and Meiosis II. Heredity is explored through the fruit fly ($Drosophila$) project, tracing traits from the parental generation to the $F_1$ generation. This includes studying gene transfer, homozygous dominance, and specific traits like eye color.

The central dogma of molecular biology is also a focus:

1. Transcription: The process of copying information from $DNA$ to $RNA$.

2. Translation: The process where $RNA$ is used to synthesize proteins at the ribosome.

Biotechnology and Microevolution

Biotechnology applications include the creation of Genetically Modified Organisms (GMOs). A primary example is the production of insulin, where human insulin genes are inserted into microbes to mass-produce the hormone. This often involves the use of a plasmid, which is the circular genome found within bacterial cells. Finally, the course touches on microevolution, examining small-scale evolutionary changes within a population over time.